GCVE Workshop - 22 September 2026 (14:00-18:00), Luxembourg Before The Vulnopticon Conference - Registration

GHSA-J9FV-QM2V-GR26

Vulnerability from github – Published: 2026-08-15 06:32 – Updated: 2026-08-17 06:33
VLAI
Details

In the Linux kernel, the following vulnerability has been resolved:

fs/ntfs3: bound DeleteIndexEntryAllocation memmove length

In do_action()'s DeleteIndexEntryAllocation case, e->size comes from an on-disk INDEX_BUFFER entry. When e->size makes e + e->size point past hdr + hdr->used, PtrOffset(e1, Add2Ptr(hdr, used)) returns a negative ptrdiff_t that is silently cast to a quasi-infinite size_t when passed to memmove(). The memmove then walks past the destination buffer.

The sibling DeleteIndexEntryRoot case at fslog.c:3540-3543 already carries the corresponding guard:

if (PtrOffset(e1, Add2Ptr(hdr, used)) < esize ||
    Add2Ptr(e, esize) > Add2Ptr(lrh, rec_len) ||
    used + esize > le32_to_cpu(hdr->total)) {
    goto dirty_vol;
}

Apply the same shape to the allocation-path case. Also reject esize == 0: memmove(e, e, ...) is a no-op and leaves hdr->used unchanged, hiding a malformed entry from the existing check_index_header() walk.

Reproduced under UML+KASAN on mainline 8d90b09e6741 by mounting a crafted NTFS image: the unguarded memmove takes a length of 0xffffffffffffff00 and the kernel oopses in memmove+0x81/0x1a0 on the do_action+0x36a2 frame.

[almaz.alexandrovich@paragon-software.com: clang-formatted the changes]

Severity
8.4 (High)
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Show details on source website
To clipboard 

{
  "affected": [],
  "aliases": [
    "CVE-2026-72197"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-08-15T06:21:38Z",
    "severity": "HIGH"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nfs/ntfs3: bound DeleteIndexEntryAllocation memmove length\n\nIn do_action()\u0027s DeleteIndexEntryAllocation case, e-\u003esize comes\nfrom an on-disk INDEX_BUFFER entry.  When e-\u003esize makes\ne + e-\u003esize point past hdr + hdr-\u003eused,\nPtrOffset(e1, Add2Ptr(hdr, used)) returns a negative ptrdiff_t\nthat is silently cast to a quasi-infinite size_t when passed\nto memmove().  The memmove then walks past the destination\nbuffer.\n\nThe sibling DeleteIndexEntryRoot case at fslog.c:3540-3543\nalready carries the corresponding guard:\n\n\tif (PtrOffset(e1, Add2Ptr(hdr, used)) \u003c esize ||\n\t    Add2Ptr(e, esize) \u003e Add2Ptr(lrh, rec_len) ||\n\t    used + esize \u003e le32_to_cpu(hdr-\u003etotal)) {\n\t\tgoto dirty_vol;\n\t}\n\nApply the same shape to the allocation-path case.  Also reject\nesize == 0: memmove(e, e, ...) is a no-op and leaves\nhdr-\u003eused unchanged, hiding a malformed entry from the\nexisting check_index_header() walk.\n\nReproduced under UML+KASAN on mainline 8d90b09e6741 by\nmounting a crafted NTFS image: the unguarded memmove takes a\nlength of 0xffffffffffffff00 and the kernel oopses in\nmemmove+0x81/0x1a0 on the do_action+0x36a2 frame.\n\n[almaz.alexandrovich@paragon-software.com: clang-formatted the changes]",
  "id": "GHSA-j9fv-qm2v-gr26",
  "modified": "2026-08-17T06:33:15Z",
  "published": "2026-08-15T06:32:15Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-72197"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/09fddd52c1b0cef2c086d61be8f3d5dc92e36565"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/4c8aac931c1cd70347961ba5157aa916448c6a25"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/554700c65d398276cb00a8ef95f1d5e00b9eff93"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/b509b9613f20dc5b653d54bf78fab00d79cc43c8"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/c38ed2ab62fab75fd6d0fdc2bee540fbebc7b959"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/f383aae59ec3994c14804f4191c59038b206be81"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/fc4626bb3656362de8b0ecd56605d47a19ec3518"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.





Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

Author Source Type Date Other

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


Detection rules are retrieved from Rulezet.